Casein/gelatin beads: I. Cross-linker solution composition effect on cross-linking degree

The effect of the cross-linker solution composition (aqueous and organic ra tio) on the cross-linking degree of hydrophilic casein/gelatin beads has be en evaluated. Casein/gelatin beads with different radii have been prepared and treated over the same time with three different cross-linker solvent co mpositions containing d,l-glyceraldehyde at the same concentration. The cro ss-linking degree was studied not only comparing the results of swelling pr ocess and degradation rate, widely reported in literature as methods for th e cross-linking degree evaluation, but also determining the solvent penetra tion rate and the d,l-glyceraldehyde reacting percentage. It has been obser ved, in fact, that the cross-linker solvent composition influences the pene tration rate through the matrix of the cross-linker, thus controlling the h omogeneity of the matrix cross-linking. (C) 1999 Elsevier Science B.V. All rights reserved.